Staff, Back-end Engineer

COUPANG ASIA HOLDINGS PTE. LTD.; Singapore; On-site; SGD 80,000 - 130,000; Full time

Job summary

A leading company in the eCommerce sector is seeking a skilled Reverse Engineer specializing in mobile applications. You will be integral in uncovering and analyzing APIs, ensuring the development of robust data extraction systems. If you excel at reverse engineering and want to impact data-driven decisions, this is the ideal opportunity.

Qualifications

• Strong experience with reverse engineering and network analysis.
• Deep understanding of mobile OS internals required.
• Experience with debugging tools is helpful.

Responsibilities

• Reverse engineer mobile applications to extract API behavior.
• Conduct static and dynamic analysis on mobile apps.
• Develop tools for hooking and data extraction.

Skills

Proficient in Python

Proficient in Java

Reverse engineering tools

Debuggers

Network traffic analysis

Mobile operating system internals

Tools

IDA Pro

Ghidra

Jadx

Binary Ninja

Radare2

JEB

x64dbg

GDB

LLDB

WinDbg

Job description

About the Role

We are seeking a highly skilled Reverse Engineer with a focus on mobile applications to uncover, analyze, and extract data from APIs used by popular eCommerce companies. This role sits at the intersection of security research, data engineering, and system-level programming. You will work closely with data teams to enable robust, scalable data pipelines by reverse-engineering client behavior and building tools to interface and extract data from undocumented APIs.

Key Responsibilities

• Reverse engineer mobile applications to extract API behavior and authentication logic.

• Perform both static and dynamic analysis on mobile apps.

• Develop and maintain tools and scripts for hooking, decryption, traffic interception, and data extraction.

• Build and manage proxy environments between mobile devices and workstations for traffic inspection.

• Create custom Proxy Toolkits to manipulate and analyze HTTP/S traffic in real time.

• Implement and maintain native code hooking using tools like Frida, Xposed, or Substrate.

• Conduct ARM/x86 Assembly analysis for deeper insights into app behavior.

• Reverse engineer web frontend logic (e.g., JavaScript obfuscation, token generation) to extract or simulate client-side API interactions.

• Ensure bypass of security features such as anti-debugging, anti-emulation, and anti-hooking.
  

Required Skills & Experience

• Proficient in Python or Java. JavaScript is helpful

• Strong experience with reverse engineering tools like IDA Pro, Ghidra, Jadx, Binary Ninja, Radare2, and JEB.

• Skilled in using debuggers (e.g., x64dbg, GDB, LLDB, WinDbg) for live process inspection.

• For mobile: Deep understanding of mobile operating system internals, including Android (AOS) and iOS, and related file formats (APK, IPA, ELF, Mach-O, PE).

• Experience with network traffic analysis, including proxy mechanics and networking protocols.

• Familiar with memory management concepts (heap/stack, paging, virtual memory) and OS architecture (Linux/macOS/Windows).
  

Nice to Have

• Experience with web crawling and scraping.

• Knowledge of kernel-level development (e.g., socket drivers).

• Prior involvement with Android rooting or iOS jailbreaking (for mobile)

• Background in working with defenders/attackers in security research settings.

• Understanding of compiler internals and code auditing practices.
  

What You’ll Build

• A high-fidelity, reliable API data extraction layer from mobile/web clients.

• Automation pipelines for decryption, API emulation, and response parsing.

• Systems to support high-throughput scraping with anti-bot and anti-fraud defenses in mind.